Java从入门到实战之（27）Java 文件操作之练习

1、文件写入和

如何使用 write() 方法向文件写入内容？

package Practice;

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;

/**
 * @program: FlinkUdf
 * @description: IO文件流
 * @author: BigData
 * @create: 2020-11-05 17:18
 **/
public class Test {
    public static void main(String[] args) {
        FileWrite("C:\文档\个人学习资料\IOTest\rainbow.txt");
    }
    /**
     * @Description: 文件写入
     * @Param: [str]
     * @return: void
     * @Author: BigData
     * @Date: 2020/11/5
     */
    private static void FileWrite(String str)
    {
        BufferedWriter out = null;
        try {
            out = new BufferedWriter(new FileWriter(str));
            out.write("文件写入");
            out.close();
            System.out.println("文件创建成功！");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

结果：

"C:Program FilesJavajdk1.8.0_221injava.exe" "-javaagent:C:Program FilesJetBrainsIntelliJ IDEA 2019.3.3libidea_rt.jar=62849:C:Program FilesJetBrainsIntelliJ IDEA 2019.3.3in" -Dfile.encoding=UTF-8 -classpath "C:Program FilesJavajdk1.8.0_221jrelibcharsets.jar;C:Program FilesJavajdk1.8.0_221jrelibdeploy.jar;C:Program FilesJavajdk1.8.0_221jrelibextaccess-bridge-64.jar;C:Program FilesJavajdk1.8.0_221jrelibextcldrdata.jar;C:Program FilesJavajdk1.8.0_221jrelibextdnsns.jar;C:Program FilesJavajdk1.8.0_221jrelibextjaccess.jar;C:Program FilesJavajdk1.8.0_221jrelibextjfxrt.jar;C:Program FilesJavajdk1.8.0_221jrelibextlocaledata.jar;C:Program FilesJavajdk1.8.0_221jrelibext
ashorn.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunec.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunjce_provider.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunmscapi.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunpkcs11.jar;C:Program FilesJavajdk1.8.0_221jrelibextzipfs.jar;C:Program FilesJavajdk1.8.0_221jrelibjavaws.jar;C:Program FilesJavajdk1.8.0_221jrelibjce.jar;C:Program FilesJavajdk1.8.0_221jrelibjfr.jar;C:Program FilesJavajdk1.8.0_221jrelibjfxswt.jar;C:Program FilesJavajdk1.8.0_221jrelibjsse.jar;C:Program FilesJavajdk1.8.0_221jrelibmanagement-agent.jar;C:Program FilesJavajdk1.8.0_221jrelibplugin.jar;C:Program FilesJavajdk1.8.0_221jrelib
esources.jar;C:Program FilesJavajdk1.8.0_221jrelib
t.jar;C:appFlinkUdf	arget	est-classes;C:Usersdefaultuser0.m2
epositoryjunitjunit4.11junit-4.11.jar;C:Usersdefaultuser0.m2
epositoryorghamcresthamcrest-core1.3hamcrest-core-1.3.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-java-bridge_2.111.11.1flink-table-api-java-bridge_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-java1.11.1flink-table-api-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-java1.11.1flink-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-lang33.3.2commons-lang3-3.3.2.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-math33.5commons-math3-3.5.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-java_2.111.11.1flink-streaming-java_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-runtime_2.111.11.1flink-runtime_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-queryable-state-client-java1.11.1flink-queryable-state-client-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-hadoop-fs1.11.1flink-hadoop-fs-1.11.1.jar;C:Usersdefaultuser0.m2
epositorycommons-iocommons-io2.4commons-io-2.4.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-netty4.1.39.Final-11.0flink-shaded-netty-4.1.39.Final-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-jackson2.10.1-11.0flink-shaded-jackson-2.10.1-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-zookeeper-33.4.14-11.0flink-shaded-zookeeper-3-3.4.14-11.0.jar;C:Usersdefaultuser0.m2
epositorycommons-clicommons-cli1.3.1commons-cli-1.3.1.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-actor_2.112.5.21akka-actor_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeconfig1.3.3config-1.3.3.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-java8-compat_2.11.7.0scala-java8-compat_2.11-0.7.0.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-stream_2.112.5.21akka-stream_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositoryorg
eactivestreams
eactive-streams1.0.2
eactive-streams-1.0.2.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafessl-config-core_2.11.3.7ssl-config-core_2.11-0.3.7.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-protobuf_2.112.5.21akka-protobuf_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-slf4j_2.112.5.21akka-slf4j_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositoryorgclappergrizzled-slf4j_2.111.3.2grizzled-slf4j_2.11-1.3.2.jar;C:Usersdefaultuser0.m2
epositorycomgithubscoptscopt_2.113.5.0scopt_2.11-3.5.0.jar;C:Usersdefaultuser0.m2
epositoryorgxerialsnappysnappy-java1.1.4snappy-java-1.1.4.jar;C:Usersdefaultuser0.m2
epositorycom	witterchill_2.11.7.6chill_2.11-0.7.6.jar;C:Usersdefaultuser0.m2
epositorycom	witterchill-java.7.6chill-java-0.7.6.jar;C:Usersdefaultuser0.m2
epositoryorglz4lz4-java1.6.0lz4-java-1.6.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-guava18.0-11.0flink-shaded-guava-18.0-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-java_2.111.11.1flink-streaming-java_2.11-1.11.1-tests.jar;C:Usersdefaultuser0.m2
epositoryorgslf4jslf4j-api1.7.15slf4j-api-1.7.15.jar;C:Usersdefaultuser0.m2
epositorycomgooglecodefindbugsjsr3051.3.9jsr305-1.3.9.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkforce-shading1.11.1force-shading-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-planner-blink_2.111.11.1flink-table-planner-blink_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-scala_2.111.11.1flink-table-api-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-scala-bridge_2.111.11.1flink-table-api-scala-bridge_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-runtime-blink_2.111.11.1flink-table-runtime-blink_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgcodehausjaninojanino3.0.9janino-3.0.9.jar;C:Usersdefaultuser0.m2
epositoryorgcodehausjaninocommons-compiler3.0.9commons-compiler-3.0.9.jar;C:Usersdefaultuser0.m2
epositoryorgapachecalciteavaticaavatica-core1.16.0avatica-core-1.16.0.jar;C:Usersdefaultuser0.m2
epositoryorg
eflections
eflections.9.10
eflections-0.9.10.jar;C:Usersdefaultuser0.m2
epositoryorgjavassistjavassist3.19.0-GAjavassist-3.19.0-GA.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-scala_2.111.11.1flink-streaming-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-scala_2.111.11.1flink-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-reflect2.11.12scala-reflect-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-library2.11.12scala-library-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-compiler2.11.12scala-compiler-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-xml_2.111.0.5scala-xml_2.11-1.0.5.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-parser-combinators_2.111.0.4scala-parser-combinators_2.11-1.0.4.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-common1.11.1flink-table-common-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-core1.11.1flink-core-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-annotations1.11.1flink-annotations-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-metrics-core1.11.1flink-metrics-core-1.11.1.jar;C:Usersdefaultuser0.m2
epositorycomesotericsoftwarekryokryo2.24.0kryo-2.24.0.jar;C:Usersdefaultuser0.m2
epositorycomesotericsoftwareminlogminlog1.2minlog-1.2.jar;C:Usersdefaultuser0.m2
epositoryorgobjenesisobjenesis2.1objenesis-2.1.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-compress1.20commons-compress-1.20.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-asm-77.1-11.0flink-shaded-asm-7-7.1-11.0.jar;C:Usersdefaultuser0.m2
epositorycomalibabafastjson1.2.73fastjson-1.2.73.jar;C:Usersdefaultuser0.m2
epositoryorgslf4jslf4j-log4j121.7.7slf4j-log4j12-1.7.7.jar;C:Usersdefaultuser0.m2
epositorylog4jlog4j1.2.17log4j-1.2.17.jar;C:Usersdefaultuser0.m2
epository
etsfjson-libjson-lib2.4json-lib-2.4-jdk15.jar;C:Usersdefaultuser0.m2
epositorycommons-beanutilscommons-beanutils1.8.0commons-beanutils-1.8.0.jar;C:Usersdefaultuser0.m2
epositorycommons-collectionscommons-collections3.2.1commons-collections-3.2.1.jar;C:Usersdefaultuser0.m2
epositorycommons-langcommons-lang2.5commons-lang-2.5.jar;C:Usersdefaultuser0.m2
epositorycommons-loggingcommons-logging1.1.1commons-logging-1.1.1.jar;C:Usersdefaultuser0.m2
epository
etsfezmorphezmorph1.0.6ezmorph-1.0.6.jar;C:Usersdefaultuser0.m2
epositoryorgjsonjson20180813json-20180813.jar" Practice.Test
文件创建成功！

Process finished with exit code 0

2、读取文件

如何使用 readLine() 方法来读取文件 test.log 内容？

package Practice;

import java.io.*;

/**
 * @program: FlinkUdf
 * @description: IO文件流
 * @author: BigData
 * @create: 2020-11-05 17:18
 **/
public class Test {
    public static void main(String[] args) {
        String str="C:\文档\个人学习资料\IOTest\rainbow.txt";
        readValue(str);
    }
    /**
     * @Description: 读取文件内容
     * @Param: [str]
     * @return: void
     * @Author: BigData
     * @Date: 2020/11/5
     */
    private static void readValue(String str)
    {
        try {
            BufferedReader in=new BufferedReader(new FileReader(str));
            String s;
            while ((s=in.readLine())!=null)
            {
                System.out.println(s);
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }
}

结果：

"C:Program FilesJavajdk1.8.0_221injava.exe" "-javaagent:C:Program FilesJetBrainsIntelliJ IDEA 2019.3.3libidea_rt.jar=62944:C:Program FilesJetBrainsIntelliJ IDEA 2019.3.3in" -Dfile.encoding=UTF-8 -classpath "C:Program FilesJavajdk1.8.0_221jrelibcharsets.jar;C:Program FilesJavajdk1.8.0_221jrelibdeploy.jar;C:Program FilesJavajdk1.8.0_221jrelibextaccess-bridge-64.jar;C:Program FilesJavajdk1.8.0_221jrelibextcldrdata.jar;C:Program FilesJavajdk1.8.0_221jrelibextdnsns.jar;C:Program FilesJavajdk1.8.0_221jrelibextjaccess.jar;C:Program FilesJavajdk1.8.0_221jrelibextjfxrt.jar;C:Program FilesJavajdk1.8.0_221jrelibextlocaledata.jar;C:Program FilesJavajdk1.8.0_221jrelibext
ashorn.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunec.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunjce_provider.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunmscapi.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunpkcs11.jar;C:Program FilesJavajdk1.8.0_221jrelibextzipfs.jar;C:Program FilesJavajdk1.8.0_221jrelibjavaws.jar;C:Program FilesJavajdk1.8.0_221jrelibjce.jar;C:Program FilesJavajdk1.8.0_221jrelibjfr.jar;C:Program FilesJavajdk1.8.0_221jrelibjfxswt.jar;C:Program FilesJavajdk1.8.0_221jrelibjsse.jar;C:Program FilesJavajdk1.8.0_221jrelibmanagement-agent.jar;C:Program FilesJavajdk1.8.0_221jrelibplugin.jar;C:Program FilesJavajdk1.8.0_221jrelib
esources.jar;C:Program FilesJavajdk1.8.0_221jrelib
t.jar;C:appFlinkUdf	arget	est-classes;C:Usersdefaultuser0.m2
epositoryjunitjunit4.11junit-4.11.jar;C:Usersdefaultuser0.m2
epositoryorghamcresthamcrest-core1.3hamcrest-core-1.3.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-java-bridge_2.111.11.1flink-table-api-java-bridge_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-java1.11.1flink-table-api-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-java1.11.1flink-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-lang33.3.2commons-lang3-3.3.2.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-math33.5commons-math3-3.5.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-java_2.111.11.1flink-streaming-java_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-runtime_2.111.11.1flink-runtime_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-queryable-state-client-java1.11.1flink-queryable-state-client-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-hadoop-fs1.11.1flink-hadoop-fs-1.11.1.jar;C:Usersdefaultuser0.m2
epositorycommons-iocommons-io2.4commons-io-2.4.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-netty4.1.39.Final-11.0flink-shaded-netty-4.1.39.Final-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-jackson2.10.1-11.0flink-shaded-jackson-2.10.1-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-zookeeper-33.4.14-11.0flink-shaded-zookeeper-3-3.4.14-11.0.jar;C:Usersdefaultuser0.m2
epositorycommons-clicommons-cli1.3.1commons-cli-1.3.1.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-actor_2.112.5.21akka-actor_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeconfig1.3.3config-1.3.3.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-java8-compat_2.11.7.0scala-java8-compat_2.11-0.7.0.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-stream_2.112.5.21akka-stream_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositoryorg
eactivestreams
eactive-streams1.0.2
eactive-streams-1.0.2.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafessl-config-core_2.11.3.7ssl-config-core_2.11-0.3.7.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-protobuf_2.112.5.21akka-protobuf_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-slf4j_2.112.5.21akka-slf4j_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositoryorgclappergrizzled-slf4j_2.111.3.2grizzled-slf4j_2.11-1.3.2.jar;C:Usersdefaultuser0.m2
epositorycomgithubscoptscopt_2.113.5.0scopt_2.11-3.5.0.jar;C:Usersdefaultuser0.m2
epositoryorgxerialsnappysnappy-java1.1.4snappy-java-1.1.4.jar;C:Usersdefaultuser0.m2
epositorycom	witterchill_2.11.7.6chill_2.11-0.7.6.jar;C:Usersdefaultuser0.m2
epositorycom	witterchill-java.7.6chill-java-0.7.6.jar;C:Usersdefaultuser0.m2
epositoryorglz4lz4-java1.6.0lz4-java-1.6.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-guava18.0-11.0flink-shaded-guava-18.0-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-java_2.111.11.1flink-streaming-java_2.11-1.11.1-tests.jar;C:Usersdefaultuser0.m2
epositoryorgslf4jslf4j-api1.7.15slf4j-api-1.7.15.jar;C:Usersdefaultuser0.m2
epositorycomgooglecodefindbugsjsr3051.3.9jsr305-1.3.9.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkforce-shading1.11.1force-shading-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-planner-blink_2.111.11.1flink-table-planner-blink_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-scala_2.111.11.1flink-table-api-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-scala-bridge_2.111.11.1flink-table-api-scala-bridge_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-runtime-blink_2.111.11.1flink-table-runtime-blink_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgcodehausjaninojanino3.0.9janino-3.0.9.jar;C:Usersdefaultuser0.m2
epositoryorgcodehausjaninocommons-compiler3.0.9commons-compiler-3.0.9.jar;C:Usersdefaultuser0.m2
epositoryorgapachecalciteavaticaavatica-core1.16.0avatica-core-1.16.0.jar;C:Usersdefaultuser0.m2
epositoryorg
eflections
eflections.9.10
eflections-0.9.10.jar;C:Usersdefaultuser0.m2
epositoryorgjavassistjavassist3.19.0-GAjavassist-3.19.0-GA.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-scala_2.111.11.1flink-streaming-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-scala_2.111.11.1flink-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-reflect2.11.12scala-reflect-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-library2.11.12scala-library-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-compiler2.11.12scala-compiler-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-xml_2.111.0.5scala-xml_2.11-1.0.5.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-parser-combinators_2.111.0.4scala-parser-combinators_2.11-1.0.4.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-common1.11.1flink-table-common-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-core1.11.1flink-core-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-annotations1.11.1flink-annotations-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-metrics-core1.11.1flink-metrics-core-1.11.1.jar;C:Usersdefaultuser0.m2
epositorycomesotericsoftwarekryokryo2.24.0kryo-2.24.0.jar;C:Usersdefaultuser0.m2
epositorycomesotericsoftwareminlogminlog1.2minlog-1.2.jar;C:Usersdefaultuser0.m2
epositoryorgobjenesisobjenesis2.1objenesis-2.1.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-compress1.20commons-compress-1.20.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-asm-77.1-11.0flink-shaded-asm-7-7.1-11.0.jar;C:Usersdefaultuser0.m2
epositorycomalibabafastjson1.2.73fastjson-1.2.73.jar;C:Usersdefaultuser0.m2
epositoryorgslf4jslf4j-log4j121.7.7slf4j-log4j12-1.7.7.jar;C:Usersdefaultuser0.m2
epositorylog4jlog4j1.2.17log4j-1.2.17.jar;C:Usersdefaultuser0.m2
epository
etsfjson-libjson-lib2.4json-lib-2.4-jdk15.jar;C:Usersdefaultuser0.m2
epositorycommons-beanutilscommons-beanutils1.8.0commons-beanutils-1.8.0.jar;C:Usersdefaultuser0.m2
epositorycommons-collectionscommons-collections3.2.1commons-collections-3.2.1.jar;C:Usersdefaultuser0.m2
epositorycommons-langcommons-lang2.5commons-lang-2.5.jar;C:Usersdefaultuser0.m2
epositorycommons-loggingcommons-logging1.1.1commons-logging-1.1.1.jar;C:Usersdefaultuser0.m2
epository
etsfezmorphezmorph1.0.6ezmorph-1.0.6.jar;C:Usersdefaultuser0.m2
epositoryorgjsonjson20180813json-20180813.jar" Practice.Test
文件写入

Process finished with exit code 0

3、删除文件

如何使用 delete() 方法将文件删除？

package Practice;

import java.io.*;

/**
 * @program: FlinkUdf
 * @description: IO文件流
 * @author: BigData
 * @create: 2020-11-05 17:18
 **/
public class Test {
    public static void main(String[] args) {
        String str="C:\文档\个人学习资料\IOTest\rainbow.txt";
        delFile(str);
    }
    /**
    * @Description: 删除文件（/+a+tab键）
    * @Param: [str]
    * @return: void
    * @Author: BigData
    * @Date: 2020/11/5
    */
    private static void  delFile(String str)
    {
        try {
            File file=new File(str);
            if(file.delete()==true)
            {
                System.out.println(file.getName()+"文件已经被删除!");
            }
            else
            {
                System.out.println("文集删除失败！");
            }
        }
        catch (Exception ex)
        {
            ex.printStackTrace();
        }
    }
}

结果：

"C:Program FilesJavajdk1.8.0_221injava.exe" "-javaagent:C:Program FilesJetBrainsIntelliJ IDEA 2019.3.3libidea_rt.jar=63028:C:Program FilesJetBrainsIntelliJ IDEA 2019.3.3in" -Dfile.encoding=UTF-8 -classpath "C:Program FilesJavajdk1.8.0_221jrelibcharsets.jar;C:Program FilesJavajdk1.8.0_221jrelibdeploy.jar;C:Program FilesJavajdk1.8.0_221jrelibextaccess-bridge-64.jar;C:Program FilesJavajdk1.8.0_221jrelibextcldrdata.jar;C:Program FilesJavajdk1.8.0_221jrelibextdnsns.jar;C:Program FilesJavajdk1.8.0_221jrelibextjaccess.jar;C:Program FilesJavajdk1.8.0_221jrelibextjfxrt.jar;C:Program FilesJavajdk1.8.0_221jrelibextlocaledata.jar;C:Program FilesJavajdk1.8.0_221jrelibext
ashorn.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunec.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunjce_provider.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunmscapi.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunpkcs11.jar;C:Program FilesJavajdk1.8.0_221jrelibextzipfs.jar;C:Program FilesJavajdk1.8.0_221jrelibjavaws.jar;C:Program FilesJavajdk1.8.0_221jrelibjce.jar;C:Program FilesJavajdk1.8.0_221jrelibjfr.jar;C:Program FilesJavajdk1.8.0_221jrelibjfxswt.jar;C:Program FilesJavajdk1.8.0_221jrelibjsse.jar;C:Program FilesJavajdk1.8.0_221jrelibmanagement-agent.jar;C:Program FilesJavajdk1.8.0_221jrelibplugin.jar;C:Program FilesJavajdk1.8.0_221jrelib
esources.jar;C:Program FilesJavajdk1.8.0_221jrelib
t.jar;C:appFlinkUdf	arget	est-classes;C:Usersdefaultuser0.m2
epositoryjunitjunit4.11junit-4.11.jar;C:Usersdefaultuser0.m2
epositoryorghamcresthamcrest-core1.3hamcrest-core-1.3.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-java-bridge_2.111.11.1flink-table-api-java-bridge_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-java1.11.1flink-table-api-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-java1.11.1flink-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-lang33.3.2commons-lang3-3.3.2.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-math33.5commons-math3-3.5.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-java_2.111.11.1flink-streaming-java_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-runtime_2.111.11.1flink-runtime_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-queryable-state-client-java1.11.1flink-queryable-state-client-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-hadoop-fs1.11.1flink-hadoop-fs-1.11.1.jar;C:Usersdefaultuser0.m2
epositorycommons-iocommons-io2.4commons-io-2.4.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-netty4.1.39.Final-11.0flink-shaded-netty-4.1.39.Final-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-jackson2.10.1-11.0flink-shaded-jackson-2.10.1-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-zookeeper-33.4.14-11.0flink-shaded-zookeeper-3-3.4.14-11.0.jar;C:Usersdefaultuser0.m2
epositorycommons-clicommons-cli1.3.1commons-cli-1.3.1.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-actor_2.112.5.21akka-actor_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeconfig1.3.3config-1.3.3.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-java8-compat_2.11.7.0scala-java8-compat_2.11-0.7.0.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-stream_2.112.5.21akka-stream_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositoryorg
eactivestreams
eactive-streams1.0.2
eactive-streams-1.0.2.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafessl-config-core_2.11.3.7ssl-config-core_2.11-0.3.7.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-protobuf_2.112.5.21akka-protobuf_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-slf4j_2.112.5.21akka-slf4j_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositoryorgclappergrizzled-slf4j_2.111.3.2grizzled-slf4j_2.11-1.3.2.jar;C:Usersdefaultuser0.m2
epositorycomgithubscoptscopt_2.113.5.0scopt_2.11-3.5.0.jar;C:Usersdefaultuser0.m2
epositoryorgxerialsnappysnappy-java1.1.4snappy-java-1.1.4.jar;C:Usersdefaultuser0.m2
epositorycom	witterchill_2.11.7.6chill_2.11-0.7.6.jar;C:Usersdefaultuser0.m2
epositorycom	witterchill-java.7.6chill-java-0.7.6.jar;C:Usersdefaultuser0.m2
epositoryorglz4lz4-java1.6.0lz4-java-1.6.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-guava18.0-11.0flink-shaded-guava-18.0-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-java_2.111.11.1flink-streaming-java_2.11-1.11.1-tests.jar;C:Usersdefaultuser0.m2
epositoryorgslf4jslf4j-api1.7.15slf4j-api-1.7.15.jar;C:Usersdefaultuser0.m2
epositorycomgooglecodefindbugsjsr3051.3.9jsr305-1.3.9.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkforce-shading1.11.1force-shading-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-planner-blink_2.111.11.1flink-table-planner-blink_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-scala_2.111.11.1flink-table-api-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-scala-bridge_2.111.11.1flink-table-api-scala-bridge_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-runtime-blink_2.111.11.1flink-table-runtime-blink_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgcodehausjaninojanino3.0.9janino-3.0.9.jar;C:Usersdefaultuser0.m2
epositoryorgcodehausjaninocommons-compiler3.0.9commons-compiler-3.0.9.jar;C:Usersdefaultuser0.m2
epositoryorgapachecalciteavaticaavatica-core1.16.0avatica-core-1.16.0.jar;C:Usersdefaultuser0.m2
epositoryorg
eflections
eflections.9.10
eflections-0.9.10.jar;C:Usersdefaultuser0.m2
epositoryorgjavassistjavassist3.19.0-GAjavassist-3.19.0-GA.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-scala_2.111.11.1flink-streaming-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-scala_2.111.11.1flink-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-reflect2.11.12scala-reflect-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-library2.11.12scala-library-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-compiler2.11.12scala-compiler-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-xml_2.111.0.5scala-xml_2.11-1.0.5.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-parser-combinators_2.111.0.4scala-parser-combinators_2.11-1.0.4.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-common1.11.1flink-table-common-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-core1.11.1flink-core-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-annotations1.11.1flink-annotations-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-metrics-core1.11.1flink-metrics-core-1.11.1.jar;C:Usersdefaultuser0.m2
epositorycomesotericsoftwarekryokryo2.24.0kryo-2.24.0.jar;C:Usersdefaultuser0.m2
epositorycomesotericsoftwareminlogminlog1.2minlog-1.2.jar;C:Usersdefaultuser0.m2
epositoryorgobjenesisobjenesis2.1objenesis-2.1.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-compress1.20commons-compress-1.20.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-asm-77.1-11.0flink-shaded-asm-7-7.1-11.0.jar;C:Usersdefaultuser0.m2
epositorycomalibabafastjson1.2.73fastjson-1.2.73.jar;C:Usersdefaultuser0.m2
epositoryorgslf4jslf4j-log4j121.7.7slf4j-log4j12-1.7.7.jar;C:Usersdefaultuser0.m2
epositorylog4jlog4j1.2.17log4j-1.2.17.jar;C:Usersdefaultuser0.m2
epository
etsfjson-libjson-lib2.4json-lib-2.4-jdk15.jar;C:Usersdefaultuser0.m2
epositorycommons-beanutilscommons-beanutils1.8.0commons-beanutils-1.8.0.jar;C:Usersdefaultuser0.m2
epositorycommons-collectionscommons-collections3.2.1commons-collections-3.2.1.jar;C:Usersdefaultuser0.m2
epositorycommons-langcommons-lang2.5commons-lang-2.5.jar;C:Usersdefaultuser0.m2
epositorycommons-loggingcommons-logging1.1.1commons-logging-1.1.1.jar;C:Usersdefaultuser0.m2
epository
etsfezmorphezmorph1.0.6ezmorph-1.0.6.jar;C:Usersdefaultuser0.m2
epositoryorgjsonjson20180813json-20180813.jar" Practice.Test
rainbow.txt文件已经被删除!

Process finished with exit code 0

4、将文件内容复制到另一个文件

package Practice;

import java.io.*;

/**
 * @program: FlinkUdf
 * @description: IO文件流
 * @author: BigData
 * @create: 2020-11-05 17:18
 **/
public class Test {
    public static void main(String[] args) {
        String str="C:\文档\个人学习资料\IOTest\rainbow.txt";
        String string="C:\文档\个人学习资料\IOTest\rainbow1.txt";
        copyFile(str,string);
    }
    /**
    * @Description: 复制文件内容到另外文件中
    * @Param: [string]
    * @return: void
    * @Author: BigData
    * @Date: 2020/11/5
    */
    private static void copyFile(String string,String string1)
    {
        try {
            BufferedWriter out=new BufferedWriter(new FileWriter(string));
            out.write("复制文件");
            out.close();
            InputStream in=new FileInputStream(new File(string));
            OutputStream out1=new FileOutputStream(new File(string1));
            byte[] buf=new byte[1024];
            int len;
            while ((len=in.read(buf))>0)
            {
                out1.write(buf,0,len);
            }
            in.close();
            out1.close();
            BufferedReader in1=new BufferedReader(new FileReader(string1));
            String s;
            while ((s=in1.readLine())!=null)
            {
                System.out.println(s);
            }
            in1.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }
}

结果：

"C:Program FilesJavajdk1.8.0_221injava.exe" "-javaagent:C:Program FilesJetBrainsIntelliJ IDEA 2019.3.3libidea_rt.jar=63140:C:Program FilesJetBrainsIntelliJ IDEA 2019.3.3in" -Dfile.encoding=UTF-8 -classpath "C:Program FilesJavajdk1.8.0_221jrelibcharsets.jar;C:Program FilesJavajdk1.8.0_221jrelibdeploy.jar;C:Program FilesJavajdk1.8.0_221jrelibextaccess-bridge-64.jar;C:Program FilesJavajdk1.8.0_221jrelibextcldrdata.jar;C:Program FilesJavajdk1.8.0_221jrelibextdnsns.jar;C:Program FilesJavajdk1.8.0_221jrelibextjaccess.jar;C:Program FilesJavajdk1.8.0_221jrelibextjfxrt.jar;C:Program FilesJavajdk1.8.0_221jrelibextlocaledata.jar;C:Program FilesJavajdk1.8.0_221jrelibext
ashorn.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunec.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunjce_provider.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunmscapi.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunpkcs11.jar;C:Program FilesJavajdk1.8.0_221jrelibextzipfs.jar;C:Program FilesJavajdk1.8.0_221jrelibjavaws.jar;C:Program FilesJavajdk1.8.0_221jrelibjce.jar;C:Program FilesJavajdk1.8.0_221jrelibjfr.jar;C:Program FilesJavajdk1.8.0_221jrelibjfxswt.jar;C:Program FilesJavajdk1.8.0_221jrelibjsse.jar;C:Program FilesJavajdk1.8.0_221jrelibmanagement-agent.jar;C:Program FilesJavajdk1.8.0_221jrelibplugin.jar;C:Program FilesJavajdk1.8.0_221jrelib
esources.jar;C:Program FilesJavajdk1.8.0_221jrelib
t.jar;C:appFlinkUdf	arget	est-classes;C:Usersdefaultuser0.m2
epositoryjunitjunit4.11junit-4.11.jar;C:Usersdefaultuser0.m2
epositoryorghamcresthamcrest-core1.3hamcrest-core-1.3.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-java-bridge_2.111.11.1flink-table-api-java-bridge_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-java1.11.1flink-table-api-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-java1.11.1flink-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-lang33.3.2commons-lang3-3.3.2.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-math33.5commons-math3-3.5.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-java_2.111.11.1flink-streaming-java_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-runtime_2.111.11.1flink-runtime_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-queryable-state-client-java1.11.1flink-queryable-state-client-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-hadoop-fs1.11.1flink-hadoop-fs-1.11.1.jar;C:Usersdefaultuser0.m2
epositorycommons-iocommons-io2.4commons-io-2.4.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-netty4.1.39.Final-11.0flink-shaded-netty-4.1.39.Final-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-jackson2.10.1-11.0flink-shaded-jackson-2.10.1-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-zookeeper-33.4.14-11.0flink-shaded-zookeeper-3-3.4.14-11.0.jar;C:Usersdefaultuser0.m2
epositorycommons-clicommons-cli1.3.1commons-cli-1.3.1.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-actor_2.112.5.21akka-actor_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeconfig1.3.3config-1.3.3.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-java8-compat_2.11.7.0scala-java8-compat_2.11-0.7.0.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-stream_2.112.5.21akka-stream_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositoryorg
eactivestreams
eactive-streams1.0.2
eactive-streams-1.0.2.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafessl-config-core_2.11.3.7ssl-config-core_2.11-0.3.7.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-protobuf_2.112.5.21akka-protobuf_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-slf4j_2.112.5.21akka-slf4j_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositoryorgclappergrizzled-slf4j_2.111.3.2grizzled-slf4j_2.11-1.3.2.jar;C:Usersdefaultuser0.m2
epositorycomgithubscoptscopt_2.113.5.0scopt_2.11-3.5.0.jar;C:Usersdefaultuser0.m2
epositoryorgxerialsnappysnappy-java1.1.4snappy-java-1.1.4.jar;C:Usersdefaultuser0.m2
epositorycom	witterchill_2.11.7.6chill_2.11-0.7.6.jar;C:Usersdefaultuser0.m2
epositorycom	witterchill-java.7.6chill-java-0.7.6.jar;C:Usersdefaultuser0.m2
epositoryorglz4lz4-java1.6.0lz4-java-1.6.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-guava18.0-11.0flink-shaded-guava-18.0-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-java_2.111.11.1flink-streaming-java_2.11-1.11.1-tests.jar;C:Usersdefaultuser0.m2
epositoryorgslf4jslf4j-api1.7.15slf4j-api-1.7.15.jar;C:Usersdefaultuser0.m2
epositorycomgooglecodefindbugsjsr3051.3.9jsr305-1.3.9.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkforce-shading1.11.1force-shading-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-planner-blink_2.111.11.1flink-table-planner-blink_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-scala_2.111.11.1flink-table-api-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-scala-bridge_2.111.11.1flink-table-api-scala-bridge_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-runtime-blink_2.111.11.1flink-table-runtime-blink_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgcodehausjaninojanino3.0.9janino-3.0.9.jar;C:Usersdefaultuser0.m2
epositoryorgcodehausjaninocommons-compiler3.0.9commons-compiler-3.0.9.jar;C:Usersdefaultuser0.m2
epositoryorgapachecalciteavaticaavatica-core1.16.0avatica-core-1.16.0.jar;C:Usersdefaultuser0.m2
epositoryorg
eflections
eflections.9.10
eflections-0.9.10.jar;C:Usersdefaultuser0.m2
epositoryorgjavassistjavassist3.19.0-GAjavassist-3.19.0-GA.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-scala_2.111.11.1flink-streaming-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-scala_2.111.11.1flink-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-reflect2.11.12scala-reflect-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-library2.11.12scala-library-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-compiler2.11.12scala-compiler-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-xml_2.111.0.5scala-xml_2.11-1.0.5.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-parser-combinators_2.111.0.4scala-parser-combinators_2.11-1.0.4.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-common1.11.1flink-table-common-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-core1.11.1flink-core-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-annotations1.11.1flink-annotations-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-metrics-core1.11.1flink-metrics-core-1.11.1.jar;C:Usersdefaultuser0.m2
epositorycomesotericsoftwarekryokryo2.24.0kryo-2.24.0.jar;C:Usersdefaultuser0.m2
epositorycomesotericsoftwareminlogminlog1.2minlog-1.2.jar;C:Usersdefaultuser0.m2
epositoryorgobjenesisobjenesis2.1objenesis-2.1.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-compress1.20commons-compress-1.20.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-asm-77.1-11.0flink-shaded-asm-7-7.1-11.0.jar;C:Usersdefaultuser0.m2
epositorycomalibabafastjson1.2.73fastjson-1.2.73.jar;C:Usersdefaultuser0.m2
epositoryorgslf4jslf4j-log4j121.7.7slf4j-log4j12-1.7.7.jar;C:Usersdefaultuser0.m2
epositorylog4jlog4j1.2.17log4j-1.2.17.jar;C:Usersdefaultuser0.m2
epository
etsfjson-libjson-lib2.4json-lib-2.4-jdk15.jar;C:Usersdefaultuser0.m2
epositorycommons-beanutilscommons-beanutils1.8.0commons-beanutils-1.8.0.jar;C:Usersdefaultuser0.m2
epositorycommons-collectionscommons-collections3.2.1commons-collections-3.2.1.jar;C:Usersdefaultuser0.m2
epositorycommons-langcommons-lang2.5commons-lang-2.5.jar;C:Usersdefaultuser0.m2
epositorycommons-loggingcommons-logging1.1.1commons-logging-1.1.1.jar;C:Usersdefaultuser0.m2
epository
etsfezmorphezmorph1.0.6ezmorph-1.0.6.jar;C:Usersdefaultuser0.m2
epositoryorgjsonjson20180813json-20180813.jar" Practice.Test
复制文件

Process finished with exit code 0

5、向文件中追加数据

package Practice;

import com.sun.org.glassfish.gmbal.Description;

import java.io.*;

/**
 * @program: FlinkUdf
 * @description: IO文件流
 * @author: BigData
 * @create: 2020-11-05 17:18
 **/
public class Test {
    public static void main(String[] args) {
        String str="C:\文档\个人学习资料\IOTest\rainbow2.txt";
        String string="追加的内容";
        appendContent(str,string);
    }
    /**
    * @Description:追加内容
    * @Param:
    * @return:
    * @Author: BigData
    * @Date: 2020/11/6
    */
   private static void appendContent(String str,String s)
   {
       try {
           BufferedWriter out=new BufferedWriter(new FileWriter(str));
           out.write("原内容--->>>>");
           out.close();
           //1.注意
           out=new BufferedWriter(new FileWriter(str,true));
           out.write(s);
           out.close();
           BufferedReader in=new BufferedReader(new FileReader(str));
           String string;
           while ((string=in.readLine())!=null)
           {
               System.out.println(string);
           }
       }
       catch (Exception ex)
       {
           System.out.println("错误内容："+ex);
       }
   }
}

结果：

"C:Program FilesJavajdk1.8.0_221injava.exe" "-javaagent:C:Program FilesJetBrainsIntelliJ IDEA 2019.3.3libidea_rt.jar=50466:C:Program FilesJetBrainsIntelliJ IDEA 2019.3.3in" -Dfile.encoding=UTF-8 -classpath "C:Program FilesJavajdk1.8.0_221jrelibcharsets.jar;C:Program FilesJavajdk1.8.0_221jrelibdeploy.jar;C:Program FilesJavajdk1.8.0_221jrelibextaccess-bridge-64.jar;C:Program FilesJavajdk1.8.0_221jrelibextcldrdata.jar;C:Program FilesJavajdk1.8.0_221jrelibextdnsns.jar;C:Program FilesJavajdk1.8.0_221jrelibextjaccess.jar;C:Program FilesJavajdk1.8.0_221jrelibextjfxrt.jar;C:Program FilesJavajdk1.8.0_221jrelibextlocaledata.jar;C:Program FilesJavajdk1.8.0_221jrelibext
ashorn.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunec.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunjce_provider.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunmscapi.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunpkcs11.jar;C:Program FilesJavajdk1.8.0_221jrelibextzipfs.jar;C:Program FilesJavajdk1.8.0_221jrelibjavaws.jar;C:Program FilesJavajdk1.8.0_221jrelibjce.jar;C:Program FilesJavajdk1.8.0_221jrelibjfr.jar;C:Program FilesJavajdk1.8.0_221jrelibjfxswt.jar;C:Program FilesJavajdk1.8.0_221jrelibjsse.jar;C:Program FilesJavajdk1.8.0_221jrelibmanagement-agent.jar;C:Program FilesJavajdk1.8.0_221jrelibplugin.jar;C:Program FilesJavajdk1.8.0_221jrelib
esources.jar;C:Program FilesJavajdk1.8.0_221jrelib
t.jar;C:appFlinkUdf	arget	est-classes;C:Usersdefaultuser0.m2
epositoryjunitjunit4.11junit-4.11.jar;C:Usersdefaultuser0.m2
epositoryorghamcresthamcrest-core1.3hamcrest-core-1.3.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-java-bridge_2.111.11.1flink-table-api-java-bridge_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-java1.11.1flink-table-api-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-java1.11.1flink-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-lang33.3.2commons-lang3-3.3.2.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-math33.5commons-math3-3.5.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-java_2.111.11.1flink-streaming-java_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-runtime_2.111.11.1flink-runtime_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-queryable-state-client-java1.11.1flink-queryable-state-client-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-hadoop-fs1.11.1flink-hadoop-fs-1.11.1.jar;C:Usersdefaultuser0.m2
epositorycommons-iocommons-io2.4commons-io-2.4.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-netty4.1.39.Final-11.0flink-shaded-netty-4.1.39.Final-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-jackson2.10.1-11.0flink-shaded-jackson-2.10.1-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-zookeeper-33.4.14-11.0flink-shaded-zookeeper-3-3.4.14-11.0.jar;C:Usersdefaultuser0.m2
epositorycommons-clicommons-cli1.3.1commons-cli-1.3.1.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-actor_2.112.5.21akka-actor_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeconfig1.3.3config-1.3.3.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-java8-compat_2.11.7.0scala-java8-compat_2.11-0.7.0.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-stream_2.112.5.21akka-stream_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositoryorg
eactivestreams
eactive-streams1.0.2
eactive-streams-1.0.2.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafessl-config-core_2.11.3.7ssl-config-core_2.11-0.3.7.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-protobuf_2.112.5.21akka-protobuf_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-slf4j_2.112.5.21akka-slf4j_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositoryorgclappergrizzled-slf4j_2.111.3.2grizzled-slf4j_2.11-1.3.2.jar;C:Usersdefaultuser0.m2
epositorycomgithubscoptscopt_2.113.5.0scopt_2.11-3.5.0.jar;C:Usersdefaultuser0.m2
epositoryorgxerialsnappysnappy-java1.1.4snappy-java-1.1.4.jar;C:Usersdefaultuser0.m2
epositorycom	witterchill_2.11.7.6chill_2.11-0.7.6.jar;C:Usersdefaultuser0.m2
epositorycom	witterchill-java.7.6chill-java-0.7.6.jar;C:Usersdefaultuser0.m2
epositoryorglz4lz4-java1.6.0lz4-java-1.6.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-guava18.0-11.0flink-shaded-guava-18.0-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-java_2.111.11.1flink-streaming-java_2.11-1.11.1-tests.jar;C:Usersdefaultuser0.m2
epositoryorgslf4jslf4j-api1.7.15slf4j-api-1.7.15.jar;C:Usersdefaultuser0.m2
epositorycomgooglecodefindbugsjsr3051.3.9jsr305-1.3.9.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkforce-shading1.11.1force-shading-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-planner-blink_2.111.11.1flink-table-planner-blink_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-scala_2.111.11.1flink-table-api-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-scala-bridge_2.111.11.1flink-table-api-scala-bridge_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-runtime-blink_2.111.11.1flink-table-runtime-blink_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgcodehausjaninojanino3.0.9janino-3.0.9.jar;C:Usersdefaultuser0.m2
epositoryorgcodehausjaninocommons-compiler3.0.9commons-compiler-3.0.9.jar;C:Usersdefaultuser0.m2
epositoryorgapachecalciteavaticaavatica-core1.16.0avatica-core-1.16.0.jar;C:Usersdefaultuser0.m2
epositoryorg
eflections
eflections.9.10
eflections-0.9.10.jar;C:Usersdefaultuser0.m2
epositoryorgjavassistjavassist3.19.0-GAjavassist-3.19.0-GA.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-scala_2.111.11.1flink-streaming-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-scala_2.111.11.1flink-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-reflect2.11.12scala-reflect-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-library2.11.12scala-library-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-compiler2.11.12scala-compiler-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-xml_2.111.0.5scala-xml_2.11-1.0.5.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-parser-combinators_2.111.0.4scala-parser-combinators_2.11-1.0.4.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-common1.11.1flink-table-common-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-core1.11.1flink-core-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-annotations1.11.1flink-annotations-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-metrics-core1.11.1flink-metrics-core-1.11.1.jar;C:Usersdefaultuser0.m2
epositorycomesotericsoftwarekryokryo2.24.0kryo-2.24.0.jar;C:Usersdefaultuser0.m2
epositorycomesotericsoftwareminlogminlog1.2minlog-1.2.jar;C:Usersdefaultuser0.m2
epositoryorgobjenesisobjenesis2.1objenesis-2.1.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-compress1.20commons-compress-1.20.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-asm-77.1-11.0flink-shaded-asm-7-7.1-11.0.jar;C:Usersdefaultuser0.m2
epositorycomalibabafastjson1.2.73fastjson-1.2.73.jar;C:Usersdefaultuser0.m2
epositoryorgslf4jslf4j-log4j121.7.7slf4j-log4j12-1.7.7.jar;C:Usersdefaultuser0.m2
epositorylog4jlog4j1.2.17log4j-1.2.17.jar;C:Usersdefaultuser0.m2
epository
etsfjson-libjson-lib2.4json-lib-2.4-jdk15.jar;C:Usersdefaultuser0.m2
epositorycommons-beanutilscommons-beanutils1.8.0commons-beanutils-1.8.0.jar;C:Usersdefaultuser0.m2
epositorycommons-collectionscommons-collections3.2.1commons-collections-3.2.1.jar;C:Usersdefaultuser0.m2
epositorycommons-langcommons-lang2.5commons-lang-2.5.jar;C:Usersdefaultuser0.m2
epositorycommons-loggingcommons-logging1.1.1commons-logging-1.1.1.jar;C:Usersdefaultuser0.m2
epository
etsfezmorphezmorph1.0.6ezmorph-1.0.6.jar;C:Usersdefaultuser0.m2
epositoryorgjsonjson20180813json-20180813.jar" Practice.Test
原内容--->>>>追加的内容

Process finished with exit code 0

6、创建临时文件

 如何使用 File 类的 createTempFile(String prefix, String suffix); 方法在默认临时目录来创建临时文件，参数 prefix 为前缀，suffix 为后缀？

package Practice;

import com.sun.org.glassfish.gmbal.Description;

import java.io.*;

/**
 * @program: FlinkUdf
 * @description: IO文件流
 * @author: BigData
 * @create: 2020-11-05 17:18
 **/
public class Test {
    public static void main(String[] args) {
        String path="C:\文档\个人学习资料\IOTest\";
        String file="test";
        String fmt=".txt";
        creatTmpFile(path,file,fmt);
    }
    /**
    * @Description: 根据文件路径，文件名和文件格式来创建临时文件
    * @Param:
    * @return:
    * @Author: BigData
    * @Date: 2020/11/9
    */
    private static  void creatTmpFile(String path,String file,String fmt)
    {
        File f=null;
        try {
            //创建临时文件
            f=File.createTempFile(file,fmt,new File(path));
            // 输出绝对路径
            System.out.println("临时文件绝对路径："+f.getAbsolutePath());
            // 终止后删除临时文件
            f.deleteOnExit();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

结果：

"C:Program FilesJavajdk1.8.0_221injava.exe" "-javaagent:C:Program FilesJetBrainsIntelliJ IDEA 2019.3.3libidea_rt.jar=54225:C:Program FilesJetBrainsIntelliJ IDEA 2019.3.3in" -Dfile.encoding=UTF-8 -classpath "C:Program FilesJavajdk1.8.0_221jrelibcharsets.jar;C:Program FilesJavajdk1.8.0_221jrelibdeploy.jar;C:Program FilesJavajdk1.8.0_221jrelibextaccess-bridge-64.jar;C:Program FilesJavajdk1.8.0_221jrelibextcldrdata.jar;C:Program FilesJavajdk1.8.0_221jrelibextdnsns.jar;C:Program FilesJavajdk1.8.0_221jrelibextjaccess.jar;C:Program FilesJavajdk1.8.0_221jrelibextjfxrt.jar;C:Program FilesJavajdk1.8.0_221jrelibextlocaledata.jar;C:Program FilesJavajdk1.8.0_221jrelibext
ashorn.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunec.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunjce_provider.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunmscapi.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunpkcs11.jar;C:Program FilesJavajdk1.8.0_221jrelibextzipfs.jar;C:Program FilesJavajdk1.8.0_221jrelibjavaws.jar;C:Program FilesJavajdk1.8.0_221jrelibjce.jar;C:Program FilesJavajdk1.8.0_221jrelibjfr.jar;C:Program FilesJavajdk1.8.0_221jrelibjfxswt.jar;C:Program FilesJavajdk1.8.0_221jrelibjsse.jar;C:Program FilesJavajdk1.8.0_221jrelibmanagement-agent.jar;C:Program FilesJavajdk1.8.0_221jrelibplugin.jar;C:Program FilesJavajdk1.8.0_221jrelib
esources.jar;C:Program FilesJavajdk1.8.0_221jrelib
t.jar;C:appFlinkUdf	arget	est-classes;C:Usersdefaultuser0.m2
epositoryjunitjunit4.11junit-4.11.jar;C:Usersdefaultuser0.m2
epositoryorghamcresthamcrest-core1.3hamcrest-core-1.3.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-java-bridge_2.111.11.1flink-table-api-java-bridge_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-java1.11.1flink-table-api-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-java1.11.1flink-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-lang33.3.2commons-lang3-3.3.2.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-math33.5commons-math3-3.5.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-java_2.111.11.1flink-streaming-java_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-runtime_2.111.11.1flink-runtime_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-queryable-state-client-java1.11.1flink-queryable-state-client-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-hadoop-fs1.11.1flink-hadoop-fs-1.11.1.jar;C:Usersdefaultuser0.m2
epositorycommons-iocommons-io2.4commons-io-2.4.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-netty4.1.39.Final-11.0flink-shaded-netty-4.1.39.Final-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-jackson2.10.1-11.0flink-shaded-jackson-2.10.1-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-zookeeper-33.4.14-11.0flink-shaded-zookeeper-3-3.4.14-11.0.jar;C:Usersdefaultuser0.m2
epositorycommons-clicommons-cli1.3.1commons-cli-1.3.1.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-actor_2.112.5.21akka-actor_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeconfig1.3.3config-1.3.3.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-java8-compat_2.11.7.0scala-java8-compat_2.11-0.7.0.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-stream_2.112.5.21akka-stream_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositoryorg
eactivestreams
eactive-streams1.0.2
eactive-streams-1.0.2.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafessl-config-core_2.11.3.7ssl-config-core_2.11-0.3.7.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-protobuf_2.112.5.21akka-protobuf_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-slf4j_2.112.5.21akka-slf4j_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositoryorgclappergrizzled-slf4j_2.111.3.2grizzled-slf4j_2.11-1.3.2.jar;C:Usersdefaultuser0.m2
epositorycomgithubscoptscopt_2.113.5.0scopt_2.11-3.5.0.jar;C:Usersdefaultuser0.m2
epositoryorgxerialsnappysnappy-java1.1.4snappy-java-1.1.4.jar;C:Usersdefaultuser0.m2
epositorycom	witterchill_2.11.7.6chill_2.11-0.7.6.jar;C:Usersdefaultuser0.m2
epositorycom	witterchill-java.7.6chill-java-0.7.6.jar;C:Usersdefaultuser0.m2
epositoryorglz4lz4-java1.6.0lz4-java-1.6.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-guava18.0-11.0flink-shaded-guava-18.0-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-java_2.111.11.1flink-streaming-java_2.11-1.11.1-tests.jar;C:Usersdefaultuser0.m2
epositoryorgslf4jslf4j-api1.7.15slf4j-api-1.7.15.jar;C:Usersdefaultuser0.m2
epositorycomgooglecodefindbugsjsr3051.3.9jsr305-1.3.9.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkforce-shading1.11.1force-shading-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-planner-blink_2.111.11.1flink-table-planner-blink_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-scala_2.111.11.1flink-table-api-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-scala-bridge_2.111.11.1flink-table-api-scala-bridge_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-runtime-blink_2.111.11.1flink-table-runtime-blink_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgcodehausjaninojanino3.0.9janino-3.0.9.jar;C:Usersdefaultuser0.m2
epositoryorgcodehausjaninocommons-compiler3.0.9commons-compiler-3.0.9.jar;C:Usersdefaultuser0.m2
epositoryorgapachecalciteavaticaavatica-core1.16.0avatica-core-1.16.0.jar;C:Usersdefaultuser0.m2
epositoryorg
eflections
eflections.9.10
eflections-0.9.10.jar;C:Usersdefaultuser0.m2
epositoryorgjavassistjavassist3.19.0-GAjavassist-3.19.0-GA.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-scala_2.111.11.1flink-streaming-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-scala_2.111.11.1flink-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-reflect2.11.12scala-reflect-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-library2.11.12scala-library-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-compiler2.11.12scala-compiler-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-xml_2.111.0.5scala-xml_2.11-1.0.5.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-parser-combinators_2.111.0.4scala-parser-combinators_2.11-1.0.4.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-common1.11.1flink-table-common-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-core1.11.1flink-core-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-annotations1.11.1flink-annotations-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-metrics-core1.11.1flink-metrics-core-1.11.1.jar;C:Usersdefaultuser0.m2
epositorycomesotericsoftwarekryokryo2.24.0kryo-2.24.0.jar;C:Usersdefaultuser0.m2
epositorycomesotericsoftwareminlogminlog1.2minlog-1.2.jar;C:Usersdefaultuser0.m2
epositoryorgobjenesisobjenesis2.1objenesis-2.1.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-compress1.20commons-compress-1.20.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-asm-77.1-11.0flink-shaded-asm-7-7.1-11.0.jar;C:Usersdefaultuser0.m2
epositorycomalibabafastjson1.2.73fastjson-1.2.73.jar;C:Usersdefaultuser0.m2
epositoryorgslf4jslf4j-log4j121.7.7slf4j-log4j12-1.7.7.jar;C:Usersdefaultuser0.m2
epositorylog4jlog4j1.2.17log4j-1.2.17.jar;C:Usersdefaultuser0.m2
epository
etsfjson-libjson-lib2.4json-lib-2.4-jdk15.jar;C:Usersdefaultuser0.m2
epositorycommons-beanutilscommons-beanutils1.8.0commons-beanutils-1.8.0.jar;C:Usersdefaultuser0.m2
epositorycommons-collectionscommons-collections3.2.1commons-collections-3.2.1.jar;C:Usersdefaultuser0.m2
epositorycommons-langcommons-lang2.5commons-lang-2.5.jar;C:Usersdefaultuser0.m2
epositorycommons-loggingcommons-logging1.1.1commons-logging-1.1.1.jar;C:Usersdefaultuser0.m2
epository
etsfezmorphezmorph1.0.6ezmorph-1.0.6.jar;C:Usersdefaultuser0.m2
epositoryorgjsonjson20180813json-20180813.jar" Practice.Test
临时文件绝对路径：C:文档个人学习资料IOTest	est8748305055128945538.txt

Process finished with exit code 0

7、修改文件最后的修改日期

 如何使用 File 类的 fileToChange.lastModified() 和 fileToChange setLastModified() 方法来修改文件最后的修改日期？

package Practice;

import com.sun.org.glassfish.gmbal.Description;

import java.io.*;
import java.util.Date;

/**
 * @program: FlinkUdf
 * @description: IO文件流
 * @author: BigData
 * @create: 2020-11-05 17:18
 **/
public class Test {
    public static void main(String[] args) {
        String path="C:\文档\个人学习资料\IOTest\rainbow.txt";
        updateFileTime(path);
    }
    /**
    * @Description: 修改文件的日期
    * @Param:
    * @return:
    * @Author: BigData
    * @Date: 2020/11/9
    */
    private static  void updateFileTime(String path)
    {
        File file=new File(path);
        try {
            file.createNewFile();
            Date date=new Date(file.lastModified());
            System.out.println(date.toString());
            System.out.println(file.setLastModified(System.currentTimeMillis()));
            date=new Date(file.lastModified());
            System.out.println(date.toString());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

结果：

"C:Program FilesJavajdk1.8.0_221injava.exe" "-javaagent:C:Program FilesJetBrainsIntelliJ IDEA 2019.3.3libidea_rt.jar=54324:C:Program FilesJetBrainsIntelliJ IDEA 2019.3.3in" -Dfile.encoding=UTF-8 -classpath "C:Program FilesJavajdk1.8.0_221jrelibcharsets.jar;C:Program FilesJavajdk1.8.0_221jrelibdeploy.jar;C:Program FilesJavajdk1.8.0_221jrelibextaccess-bridge-64.jar;C:Program FilesJavajdk1.8.0_221jrelibextcldrdata.jar;C:Program FilesJavajdk1.8.0_221jrelibextdnsns.jar;C:Program FilesJavajdk1.8.0_221jrelibextjaccess.jar;C:Program FilesJavajdk1.8.0_221jrelibextjfxrt.jar;C:Program FilesJavajdk1.8.0_221jrelibextlocaledata.jar;C:Program FilesJavajdk1.8.0_221jrelibext
ashorn.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunec.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunjce_provider.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunmscapi.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunpkcs11.jar;C:Program FilesJavajdk1.8.0_221jrelibextzipfs.jar;C:Program FilesJavajdk1.8.0_221jrelibjavaws.jar;C:Program FilesJavajdk1.8.0_221jrelibjce.jar;C:Program FilesJavajdk1.8.0_221jrelibjfr.jar;C:Program FilesJavajdk1.8.0_221jrelibjfxswt.jar;C:Program FilesJavajdk1.8.0_221jrelibjsse.jar;C:Program FilesJavajdk1.8.0_221jrelibmanagement-agent.jar;C:Program FilesJavajdk1.8.0_221jrelibplugin.jar;C:Program FilesJavajdk1.8.0_221jrelib
esources.jar;C:Program FilesJavajdk1.8.0_221jrelib
t.jar;C:appFlinkUdf	arget	est-classes;C:Usersdefaultuser0.m2
epositoryjunitjunit4.11junit-4.11.jar;C:Usersdefaultuser0.m2
epositoryorghamcresthamcrest-core1.3hamcrest-core-1.3.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-java-bridge_2.111.11.1flink-table-api-java-bridge_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-java1.11.1flink-table-api-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-java1.11.1flink-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-lang33.3.2commons-lang3-3.3.2.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-math33.5commons-math3-3.5.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-java_2.111.11.1flink-streaming-java_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-runtime_2.111.11.1flink-runtime_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-queryable-state-client-java1.11.1flink-queryable-state-client-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-hadoop-fs1.11.1flink-hadoop-fs-1.11.1.jar;C:Usersdefaultuser0.m2
epositorycommons-iocommons-io2.4commons-io-2.4.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-netty4.1.39.Final-11.0flink-shaded-netty-4.1.39.Final-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-jackson2.10.1-11.0flink-shaded-jackson-2.10.1-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-zookeeper-33.4.14-11.0flink-shaded-zookeeper-3-3.4.14-11.0.jar;C:Usersdefaultuser0.m2
epositorycommons-clicommons-cli1.3.1commons-cli-1.3.1.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-actor_2.112.5.21akka-actor_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeconfig1.3.3config-1.3.3.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-java8-compat_2.11.7.0scala-java8-compat_2.11-0.7.0.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-stream_2.112.5.21akka-stream_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositoryorg
eactivestreams
eactive-streams1.0.2
eactive-streams-1.0.2.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafessl-config-core_2.11.3.7ssl-config-core_2.11-0.3.7.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-protobuf_2.112.5.21akka-protobuf_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-slf4j_2.112.5.21akka-slf4j_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositoryorgclappergrizzled-slf4j_2.111.3.2grizzled-slf4j_2.11-1.3.2.jar;C:Usersdefaultuser0.m2
epositorycomgithubscoptscopt_2.113.5.0scopt_2.11-3.5.0.jar;C:Usersdefaultuser0.m2
epositoryorgxerialsnappysnappy-java1.1.4snappy-java-1.1.4.jar;C:Usersdefaultuser0.m2
epositorycom	witterchill_2.11.7.6chill_2.11-0.7.6.jar;C:Usersdefaultuser0.m2
epositorycom	witterchill-java.7.6chill-java-0.7.6.jar;C:Usersdefaultuser0.m2
epositoryorglz4lz4-java1.6.0lz4-java-1.6.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-guava18.0-11.0flink-shaded-guava-18.0-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-java_2.111.11.1flink-streaming-java_2.11-1.11.1-tests.jar;C:Usersdefaultuser0.m2
epositoryorgslf4jslf4j-api1.7.15slf4j-api-1.7.15.jar;C:Usersdefaultuser0.m2
epositorycomgooglecodefindbugsjsr3051.3.9jsr305-1.3.9.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkforce-shading1.11.1force-shading-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-planner-blink_2.111.11.1flink-table-planner-blink_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-scala_2.111.11.1flink-table-api-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-scala-bridge_2.111.11.1flink-table-api-scala-bridge_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-runtime-blink_2.111.11.1flink-table-runtime-blink_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgcodehausjaninojanino3.0.9janino-3.0.9.jar;C:Usersdefaultuser0.m2
epositoryorgcodehausjaninocommons-compiler3.0.9commons-compiler-3.0.9.jar;C:Usersdefaultuser0.m2
epositoryorgapachecalciteavaticaavatica-core1.16.0avatica-core-1.16.0.jar;C:Usersdefaultuser0.m2
epositoryorg
eflections
eflections.9.10
eflections-0.9.10.jar;C:Usersdefaultuser0.m2
epositoryorgjavassistjavassist3.19.0-GAjavassist-3.19.0-GA.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-scala_2.111.11.1flink-streaming-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-scala_2.111.11.1flink-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-reflect2.11.12scala-reflect-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-library2.11.12scala-library-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-compiler2.11.12scala-compiler-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-xml_2.111.0.5scala-xml_2.11-1.0.5.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-parser-combinators_2.111.0.4scala-parser-combinators_2.11-1.0.4.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-common1.11.1flink-table-common-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-core1.11.1flink-core-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-annotations1.11.1flink-annotations-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-metrics-core1.11.1flink-metrics-core-1.11.1.jar;C:Usersdefaultuser0.m2
epositorycomesotericsoftwarekryokryo2.24.0kryo-2.24.0.jar;C:Usersdefaultuser0.m2
epositorycomesotericsoftwareminlogminlog1.2minlog-1.2.jar;C:Usersdefaultuser0.m2
epositoryorgobjenesisobjenesis2.1objenesis-2.1.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-compress1.20commons-compress-1.20.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-asm-77.1-11.0flink-shaded-asm-7-7.1-11.0.jar;C:Usersdefaultuser0.m2
epositorycomalibabafastjson1.2.73fastjson-1.2.73.jar;C:Usersdefaultuser0.m2
epositoryorgslf4jslf4j-log4j121.7.7slf4j-log4j12-1.7.7.jar;C:Usersdefaultuser0.m2
epositorylog4jlog4j1.2.17log4j-1.2.17.jar;C:Usersdefaultuser0.m2
epository
etsfjson-libjson-lib2.4json-lib-2.4-jdk15.jar;C:Usersdefaultuser0.m2
epositorycommons-beanutilscommons-beanutils1.8.0commons-beanutils-1.8.0.jar;C:Usersdefaultuser0.m2
epositorycommons-collectionscommons-collections3.2.1commons-collections-3.2.1.jar;C:Usersdefaultuser0.m2
epositorycommons-langcommons-lang2.5commons-lang-2.5.jar;C:Usersdefaultuser0.m2
epositorycommons-loggingcommons-logging1.1.1commons-logging-1.1.1.jar;C:Usersdefaultuser0.m2
epository
etsfezmorphezmorph1.0.6ezmorph-1.0.6.jar;C:Usersdefaultuser0.m2
epositoryorgjsonjson20180813json-20180813.jar" Practice.Test
Thu Nov 05 17:42:25 CST 2020
true
Mon Nov 09 09:40:12 CST 2020

Process finished with exit code 0

8、获取文件大小

 如何使用 File 类的 file.exists() 和 file.length() 方法来获取文件大小，以字节计算（1KB=1024字节 ）？

package Practice;

import com.sun.org.glassfish.gmbal.Description;

import java.io.*;
import java.util.Date;

/**
 * @program: FlinkUdf
 * @description: IO文件流
 * @author: BigData
 * @create: 2020-11-05 17:18
 **/
public class Test {
    public static void main(String[] args) {
        String path="C:\文档\个人学习资料\IOTest\rainbow.txt";
        System.out.println(path+"的文件大小是："+getFileSize(path));
    }
    /**
    * @Description: 获取文件的大小
    * @Param: [filename]
    * @return: long
    * @Author: BigData
    * @Date: 2020/11/9
    */
    public static long getFileSize(String filename) {
        File file = new File(filename);
        if (!file.exists() || !file.isFile()) {
            System.out.println("文件不存在");
            return -1;
        }
        return file.length();
    }
}

结果：

"C:Program FilesJavajdk1.8.0_221injava.exe" "-javaagent:C:Program FilesJetBrainsIntelliJ IDEA 2019.3.3libidea_rt.jar=54409:C:Program FilesJetBrainsIntelliJ IDEA 2019.3.3in" -Dfile.encoding=UTF-8 -classpath "C:Program FilesJavajdk1.8.0_221jrelibcharsets.jar;C:Program FilesJavajdk1.8.0_221jrelibdeploy.jar;C:Program FilesJavajdk1.8.0_221jrelibextaccess-bridge-64.jar;C:Program FilesJavajdk1.8.0_221jrelibextcldrdata.jar;C:Program FilesJavajdk1.8.0_221jrelibextdnsns.jar;C:Program FilesJavajdk1.8.0_221jrelibextjaccess.jar;C:Program FilesJavajdk1.8.0_221jrelibextjfxrt.jar;C:Program FilesJavajdk1.8.0_221jrelibextlocaledata.jar;C:Program FilesJavajdk1.8.0_221jrelibext
ashorn.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunec.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunjce_provider.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunmscapi.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunpkcs11.jar;C:Program FilesJavajdk1.8.0_221jrelibextzipfs.jar;C:Program FilesJavajdk1.8.0_221jrelibjavaws.jar;C:Program FilesJavajdk1.8.0_221jrelibjce.jar;C:Program FilesJavajdk1.8.0_221jrelibjfr.jar;C:Program FilesJavajdk1.8.0_221jrelibjfxswt.jar;C:Program FilesJavajdk1.8.0_221jrelibjsse.jar;C:Program FilesJavajdk1.8.0_221jrelibmanagement-agent.jar;C:Program FilesJavajdk1.8.0_221jrelibplugin.jar;C:Program FilesJavajdk1.8.0_221jrelib
esources.jar;C:Program FilesJavajdk1.8.0_221jrelib
t.jar;C:appFlinkUdf	arget	est-classes;C:Usersdefaultuser0.m2
epositoryjunitjunit4.11junit-4.11.jar;C:Usersdefaultuser0.m2
epositoryorghamcresthamcrest-core1.3hamcrest-core-1.3.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-java-bridge_2.111.11.1flink-table-api-java-bridge_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-java1.11.1flink-table-api-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-java1.11.1flink-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-lang33.3.2commons-lang3-3.3.2.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-math33.5commons-math3-3.5.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-java_2.111.11.1flink-streaming-java_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-runtime_2.111.11.1flink-runtime_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-queryable-state-client-java1.11.1flink-queryable-state-client-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-hadoop-fs1.11.1flink-hadoop-fs-1.11.1.jar;C:Usersdefaultuser0.m2
epositorycommons-iocommons-io2.4commons-io-2.4.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-netty4.1.39.Final-11.0flink-shaded-netty-4.1.39.Final-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-jackson2.10.1-11.0flink-shaded-jackson-2.10.1-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-zookeeper-33.4.14-11.0flink-shaded-zookeeper-3-3.4.14-11.0.jar;C:Usersdefaultuser0.m2
epositorycommons-clicommons-cli1.3.1commons-cli-1.3.1.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-actor_2.112.5.21akka-actor_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeconfig1.3.3config-1.3.3.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-java8-compat_2.11.7.0scala-java8-compat_2.11-0.7.0.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-stream_2.112.5.21akka-stream_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositoryorg
eactivestreams
eactive-streams1.0.2
eactive-streams-1.0.2.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafessl-config-core_2.11.3.7ssl-config-core_2.11-0.3.7.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-protobuf_2.112.5.21akka-protobuf_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-slf4j_2.112.5.21akka-slf4j_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositoryorgclappergrizzled-slf4j_2.111.3.2grizzled-slf4j_2.11-1.3.2.jar;C:Usersdefaultuser0.m2
epositorycomgithubscoptscopt_2.113.5.0scopt_2.11-3.5.0.jar;C:Usersdefaultuser0.m2
epositoryorgxerialsnappysnappy-java1.1.4snappy-java-1.1.4.jar;C:Usersdefaultuser0.m2
epositorycom	witterchill_2.11.7.6chill_2.11-0.7.6.jar;C:Usersdefaultuser0.m2
epositorycom	witterchill-java.7.6chill-java-0.7.6.jar;C:Usersdefaultuser0.m2
epositoryorglz4lz4-java1.6.0lz4-java-1.6.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-guava18.0-11.0flink-shaded-guava-18.0-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-java_2.111.11.1flink-streaming-java_2.11-1.11.1-tests.jar;C:Usersdefaultuser0.m2
epositoryorgslf4jslf4j-api1.7.15slf4j-api-1.7.15.jar;C:Usersdefaultuser0.m2
epositorycomgooglecodefindbugsjsr3051.3.9jsr305-1.3.9.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkforce-shading1.11.1force-shading-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-planner-blink_2.111.11.1flink-table-planner-blink_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-scala_2.111.11.1flink-table-api-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-scala-bridge_2.111.11.1flink-table-api-scala-bridge_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-runtime-blink_2.111.11.1flink-table-runtime-blink_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgcodehausjaninojanino3.0.9janino-3.0.9.jar;C:Usersdefaultuser0.m2
epositoryorgcodehausjaninocommons-compiler3.0.9commons-compiler-3.0.9.jar;C:Usersdefaultuser0.m2
epositoryorgapachecalciteavaticaavatica-core1.16.0avatica-core-1.16.0.jar;C:Usersdefaultuser0.m2
epositoryorg
eflections
eflections.9.10
eflections-0.9.10.jar;C:Usersdefaultuser0.m2
epositoryorgjavassistjavassist3.19.0-GAjavassist-3.19.0-GA.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-scala_2.111.11.1flink-streaming-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-scala_2.111.11.1flink-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-reflect2.11.12scala-reflect-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-library2.11.12scala-library-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-compiler2.11.12scala-compiler-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-xml_2.111.0.5scala-xml_2.11-1.0.5.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-parser-combinators_2.111.0.4scala-parser-combinators_2.11-1.0.4.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-common1.11.1flink-table-common-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-core1.11.1flink-core-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-annotations1.11.1flink-annotations-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-metrics-core1.11.1flink-metrics-core-1.11.1.jar;C:Usersdefaultuser0.m2
epositorycomesotericsoftwarekryokryo2.24.0kryo-2.24.0.jar;C:Usersdefaultuser0.m2
epositorycomesotericsoftwareminlogminlog1.2minlog-1.2.jar;C:Usersdefaultuser0.m2
epositoryorgobjenesisobjenesis2.1objenesis-2.1.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-compress1.20commons-compress-1.20.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-asm-77.1-11.0flink-shaded-asm-7-7.1-11.0.jar;C:Usersdefaultuser0.m2
epositorycomalibabafastjson1.2.73fastjson-1.2.73.jar;C:Usersdefaultuser0.m2
epositoryorgslf4jslf4j-log4j121.7.7slf4j-log4j12-1.7.7.jar;C:Usersdefaultuser0.m2
epositorylog4jlog4j1.2.17log4j-1.2.17.jar;C:Usersdefaultuser0.m2
epository
etsfjson-libjson-lib2.4json-lib-2.4-jdk15.jar;C:Usersdefaultuser0.m2
epositorycommons-beanutilscommons-beanutils1.8.0commons-beanutils-1.8.0.jar;C:Usersdefaultuser0.m2
epositorycommons-collectionscommons-collections3.2.1commons-collections-3.2.1.jar;C:Usersdefaultuser0.m2
epositorycommons-langcommons-lang2.5commons-lang-2.5.jar;C:Usersdefaultuser0.m2
epositorycommons-loggingcommons-logging1.1.1commons-logging-1.1.1.jar;C:Usersdefaultuser0.m2
epository
etsfezmorphezmorph1.0.6ezmorph-1.0.6.jar;C:Usersdefaultuser0.m2
epositoryorgjsonjson20180813json-20180813.jar" Practice.Test
C:文档个人学习资料IOTest
ainbow.txt的文件大小是：12

Process finished with exit code 0

9、文件重命名

package Practice;

import com.sun.org.glassfish.gmbal.Description;

import java.io.File;
import java.io.IOException;

/**
 * @program: FlinkUdf
 * @description: IO文件流
 * @author: BigData
 * @create: 2020-11-05 17:18
 **/
public class Test {
    public static void main(String[] args) {
        String oldName="C:\文档\个人学习资料\IOTest\rainbow.txt";
        String newName="C:\文档\个人学习资料\IOTest\rainbowTest.txt";
        renameFileName(oldName,newName);
    }
    /**
    * @Description: 重命名文件名
    * @Param:
    * @return:
    * @Author: BigData
    * @Date: 2020/11/9
    */
    public static void renameFileName(String oldName,String newName) {
        File oldFile=new File(oldName);
        File newFile=new File(newName);
        if(newFile.exists())
        {
            try {
                throw new java.io.IOException("文件已经存在");
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        if(oldFile.renameTo(newFile))
        {
            System.out.println(oldName+"重命名为:"+newName);
        }
        else
        {
            System.out.println("错误命名");
        }
    }
}

结果：

"C:Program FilesJavajdk1.8.0_221injava.exe" "-javaagent:C:Program FilesJetBrainsIntelliJ IDEA 2019.3.3libidea_rt.jar=54757:C:Program FilesJetBrainsIntelliJ IDEA 2019.3.3in" -Dfile.encoding=UTF-8 -classpath "C:Program FilesJavajdk1.8.0_221jrelibcharsets.jar;C:Program FilesJavajdk1.8.0_221jrelibdeploy.jar;C:Program FilesJavajdk1.8.0_221jrelibextaccess-bridge-64.jar;C:Program FilesJavajdk1.8.0_221jrelibextcldrdata.jar;C:Program FilesJavajdk1.8.0_221jrelibextdnsns.jar;C:Program FilesJavajdk1.8.0_221jrelibextjaccess.jar;C:Program FilesJavajdk1.8.0_221jrelibextjfxrt.jar;C:Program FilesJavajdk1.8.0_221jrelibextlocaledata.jar;C:Program FilesJavajdk1.8.0_221jrelibext
ashorn.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunec.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunjce_provider.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunmscapi.jar;C:Program FilesJavajdk1.8.0_221jrelibextsunpkcs11.jar;C:Program FilesJavajdk1.8.0_221jrelibextzipfs.jar;C:Program FilesJavajdk1.8.0_221jrelibjavaws.jar;C:Program FilesJavajdk1.8.0_221jrelibjce.jar;C:Program FilesJavajdk1.8.0_221jrelibjfr.jar;C:Program FilesJavajdk1.8.0_221jrelibjfxswt.jar;C:Program FilesJavajdk1.8.0_221jrelibjsse.jar;C:Program FilesJavajdk1.8.0_221jrelibmanagement-agent.jar;C:Program FilesJavajdk1.8.0_221jrelibplugin.jar;C:Program FilesJavajdk1.8.0_221jrelib
esources.jar;C:Program FilesJavajdk1.8.0_221jrelib
t.jar;C:appFlinkUdf	arget	est-classes;C:Usersdefaultuser0.m2
epositoryjunitjunit4.11junit-4.11.jar;C:Usersdefaultuser0.m2
epositoryorghamcresthamcrest-core1.3hamcrest-core-1.3.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-java-bridge_2.111.11.1flink-table-api-java-bridge_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-java1.11.1flink-table-api-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-java1.11.1flink-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-lang33.3.2commons-lang3-3.3.2.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-math33.5commons-math3-3.5.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-java_2.111.11.1flink-streaming-java_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-runtime_2.111.11.1flink-runtime_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-queryable-state-client-java1.11.1flink-queryable-state-client-java-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-hadoop-fs1.11.1flink-hadoop-fs-1.11.1.jar;C:Usersdefaultuser0.m2
epositorycommons-iocommons-io2.4commons-io-2.4.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-netty4.1.39.Final-11.0flink-shaded-netty-4.1.39.Final-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-jackson2.10.1-11.0flink-shaded-jackson-2.10.1-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-zookeeper-33.4.14-11.0flink-shaded-zookeeper-3-3.4.14-11.0.jar;C:Usersdefaultuser0.m2
epositorycommons-clicommons-cli1.3.1commons-cli-1.3.1.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-actor_2.112.5.21akka-actor_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeconfig1.3.3config-1.3.3.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-java8-compat_2.11.7.0scala-java8-compat_2.11-0.7.0.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-stream_2.112.5.21akka-stream_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositoryorg
eactivestreams
eactive-streams1.0.2
eactive-streams-1.0.2.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafessl-config-core_2.11.3.7ssl-config-core_2.11-0.3.7.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-protobuf_2.112.5.21akka-protobuf_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositorycom	ypesafeakkaakka-slf4j_2.112.5.21akka-slf4j_2.11-2.5.21.jar;C:Usersdefaultuser0.m2
epositoryorgclappergrizzled-slf4j_2.111.3.2grizzled-slf4j_2.11-1.3.2.jar;C:Usersdefaultuser0.m2
epositorycomgithubscoptscopt_2.113.5.0scopt_2.11-3.5.0.jar;C:Usersdefaultuser0.m2
epositoryorgxerialsnappysnappy-java1.1.4snappy-java-1.1.4.jar;C:Usersdefaultuser0.m2
epositorycom	witterchill_2.11.7.6chill_2.11-0.7.6.jar;C:Usersdefaultuser0.m2
epositorycom	witterchill-java.7.6chill-java-0.7.6.jar;C:Usersdefaultuser0.m2
epositoryorglz4lz4-java1.6.0lz4-java-1.6.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-guava18.0-11.0flink-shaded-guava-18.0-11.0.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-java_2.111.11.1flink-streaming-java_2.11-1.11.1-tests.jar;C:Usersdefaultuser0.m2
epositoryorgslf4jslf4j-api1.7.15slf4j-api-1.7.15.jar;C:Usersdefaultuser0.m2
epositorycomgooglecodefindbugsjsr3051.3.9jsr305-1.3.9.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkforce-shading1.11.1force-shading-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-planner-blink_2.111.11.1flink-table-planner-blink_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-scala_2.111.11.1flink-table-api-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-api-scala-bridge_2.111.11.1flink-table-api-scala-bridge_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-runtime-blink_2.111.11.1flink-table-runtime-blink_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgcodehausjaninojanino3.0.9janino-3.0.9.jar;C:Usersdefaultuser0.m2
epositoryorgcodehausjaninocommons-compiler3.0.9commons-compiler-3.0.9.jar;C:Usersdefaultuser0.m2
epositoryorgapachecalciteavaticaavatica-core1.16.0avatica-core-1.16.0.jar;C:Usersdefaultuser0.m2
epositoryorg
eflections
eflections.9.10
eflections-0.9.10.jar;C:Usersdefaultuser0.m2
epositoryorgjavassistjavassist3.19.0-GAjavassist-3.19.0-GA.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-streaming-scala_2.111.11.1flink-streaming-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-scala_2.111.11.1flink-scala_2.11-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-reflect2.11.12scala-reflect-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-library2.11.12scala-library-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langscala-compiler2.11.12scala-compiler-2.11.12.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-xml_2.111.0.5scala-xml_2.11-1.0.5.jar;C:Usersdefaultuser0.m2
epositoryorgscala-langmodulesscala-parser-combinators_2.111.0.4scala-parser-combinators_2.11-1.0.4.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-table-common1.11.1flink-table-common-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-core1.11.1flink-core-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-annotations1.11.1flink-annotations-1.11.1.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-metrics-core1.11.1flink-metrics-core-1.11.1.jar;C:Usersdefaultuser0.m2
epositorycomesotericsoftwarekryokryo2.24.0kryo-2.24.0.jar;C:Usersdefaultuser0.m2
epositorycomesotericsoftwareminlogminlog1.2minlog-1.2.jar;C:Usersdefaultuser0.m2
epositoryorgobjenesisobjenesis2.1objenesis-2.1.jar;C:Usersdefaultuser0.m2
epositoryorgapachecommonscommons-compress1.20commons-compress-1.20.jar;C:Usersdefaultuser0.m2
epositoryorgapacheflinkflink-shaded-asm-77.1-11.0flink-shaded-asm-7-7.1-11.0.jar;C:Usersdefaultuser0.m2
epositorycomalibabafastjson1.2.73fastjson-1.2.73.jar;C:Usersdefaultuser0.m2
epositoryorgslf4jslf4j-log4j121.7.7slf4j-log4j12-1.7.7.jar;C:Usersdefaultuser0.m2
epositorylog4jlog4j1.2.17log4j-1.2.17.jar;C:Usersdefaultuser0.m2
epository
etsfjson-libjson-lib2.4json-lib-2.4-jdk15.jar;C:Usersdefaultuser0.m2
epositorycommons-beanutilscommons-beanutils1.8.0commons-beanutils-1.8.0.jar;C:Usersdefaultuser0.m2
epositorycommons-collectionscommons-collections3.2.1commons-collections-3.2.1.jar;C:Usersdefaultuser0.m2
epositorycommons-langcommons-lang2.5commons-lang-2.5.jar;C:Usersdefaultuser0.m2
epositorycommons-loggingcommons-logging1.1.1commons-logging-1.1.1.jar;C:Usersdefaultuser0.m2
epository
etsfezmorphezmorph1.0.6ezmorph-1.0.6.jar;C:Usersdefaultuser0.m2
epositoryorgjsonjson20180813json-20180813.jar" Practice.Test
C:文档个人学习资料IOTest
ainbow.txt重命名为:C:文档个人学习资料IOTest
ainbowTest.txt

Process finished with exit code 0

10、设置文件只读

 使用 File 类的 file.setReadOnly() 和 file.canWrite() 方法来设置文件只读

import java.io.File;
 
public class Main {
    public static void main(String[] args) {
        File file = new File("C:/java.txt");
        System.out.println(file.setReadOnly());
        System.out.println(file.canWrite());
    }
}

结果：

true
false

11、检测文件是否存在

使用 File 类的 file.exists() 方法来检测文件是否存在

import java.io.File;
 
public class Main {
    public static void main(String[] args) {
        File file = new File("C:/java.txt");
        System.out.println(file.exists());
    }
}

12、在指定目录中创建文件

import java.io.File;
 
public class Main {
    public static void main(String[] args) throws Exception {
        File file = null;
        File dir = new File("C:/");
        file = File.createTempFile
        ("JavaTemp", ".javatemp", dir);
        System.out.println(file.getPath());
    }

结果：

C:JavaTemp37056.javatemp

13、获取文件修改时间

import java.io.File;
import java.util.Date;
 
public class Main {
    public static void main(String[] args) {
        File file = new File("Main.java");
        Long lastModified = file.lastModified();
        Date date = new Date(lastModified);
        System.out.println(date);
    }
}

结果：

Thu Apr 09 09:40:19 CST 2015

14、创建文件

import java.io.File;
import java.io.IOException;
 
public class Main {
    public static void main(String[] args) {
        try{
            File file = new File("C:/myfile.txt");
            if(file.createNewFile())
                System.out.println("文件创建成功！");
            else
                System.out.println("出错了，该文件已经存在。");
        }
        catch(IOException ioe) {
            ioe.printStackTrace();
        }
    }
}

结果：

文件创建成功！

15、文件路径比较

使用 File 类的 filename.compareTo (another filename) 方法来比较两个文件路径是否在同一个目录下：

import java.io.File;
 
public class Main {
    public static void main(String[] args) {
        File file1 = new File("C:/File/demo1.txt");
        File file2 = new File("C:/java/demo1.txt");
        if(file1.compareTo(file2) == 0) {
            System.out.println("文件路径一致！");
        } else {
            System.out.println("文件路径不一致！");
        }
    }
}

结果：

文件路径不一致！